130 resultados para asymmetric preferences
Resumo:
A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (−)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (−)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama’s (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor’s original (3R)-stereostructure for (+)-inthomycin C is correct.
Resumo:
This paper presents a seismic response investigation into a code designed concentrically braced frame structure that is subjected to but not designed for in-plan mass eccentricity. The structure has an accidental uneven distribution of mass in plan resulting in an increased torsional component of vibration. The level of inelasticity that key structural elements in plan mass asymmetric structures are subjected to is important when analysing their ability to sustain uneven seismic demands. In-plan mass asymmetry of moment resisting frame and shear wall type structures have received significant investigation, however, the plan asymmetric response of braced frame type structures is less well understood. A three-dimensional non-linear time history analysis (NLTHA) model is created to capture the torsional response of the plan mass asymmetric structure to quantify the additional ductility demand, interstorey drifts and floor rotations. Results show that the plan mass asymmetric structure performs well in terms of ductility demand, but poorly in terms of interstorey drifts and floor rotations when compared to the plan mass symmetric structure. New linear relationships are developed between the normalised ductility demand and normalised slenderness of the bracing on the sides of the plan mass symmetric/asymmetric structures that the mass is distributed towards and away from.
Resumo:
In trying to understand the effects of political parties on shaping the voting behaviour of legislators, research has attempted the difficult task of separating the effects of preferences from rules used by party leaders to enforce discipline. However, little research has explored the prospect that party labels also reflect a social identity that is independent of legislators’ preferences and the rules used by party leaders to enforce discipline. In this study we examine that possibility, employing a data set that permits us to control both for leadership-based effects and legislator preferences on a 2000 free vote dealing with stem cell research. Using the British Representation Studies 1997 – which interviewed Members of Parliament regarding their preferences on several key issues related to the bill – we find significant evidence that party-as-identification plays a role in shaping how legislators vote, even after preferences and discipline are accounted for.
Resumo:
OBJECTIVE: To understand patients' preferences for physician behaviours during end-of-life communication.
METHODS: We used interpretive description methods to analyse data from semistructured, one-on-one interviews with patients admitted to general medical wards at three Canadian tertiary care hospitals. Study recruitment took place from October 2012 to August 2013. We used a purposive, maximum variation sampling approach to recruit hospitalised patients aged ≥55 years with a high risk of mortality within 6-12 months, and with different combinations of the following demographic variables: race (Caucasian vs non-Caucasian), gender and diagnosis (cancer vs non-cancer).
RESULTS: A total of 16 participants were recruited, most of whom (69%) were women and 70% had a non-cancer diagnosis. Two major concepts regarding helpful physician behaviour during end-of-life conversations emerged: (1) 'knowing me', which reflects the importance of acknowledging the influence of family roles and life history on values and priorities expressed during end-of-life communication, and (2) 'conditional candour', which describes a process of information exchange that includes an assessment of patients' readiness, being invited to the conversation, and sensitive delivery of information.
CONCLUSIONS: Our findings suggest that patients prefer a nuanced approach to truth telling when having end-of-life discussions with their physician. This may have important implications for clinical practice and end-of-life communication training initiatives.
Resumo:
There is increasing appreciation that hosts in natural populations are subject to infection by multiple parasite species. Yet the epidemiological and ecological processes determining the outcome of mixed infections are poorly understood. Here, we use two intracellular gut parasites (Microsporidia), one exotic and one co-evolved in the western honeybee (Apis mellifera), in an experiment in which either one or both parasites were administered either simultaneously or sequentially. We provide clear evidence of within-host competition; order of infection was an important determinant of the competitive outcome between parasites, with the first parasite significantly inhibiting the growth of the second, regardless of species. However, the strength of this ‘priority effect’ was highly asymmetric, with the exotic Nosema ceranae exhibiting stronger inhibition of Nosema apis than vice versa. Our results reveal an unusual asymmetry in parasite competition that is dependent on order of infection. When incorporated into a mathematical model of disease prevalence, we find asymmetric competition to be an important predictor of the patterns of parasite prevalence found in nature. Our findings demonstrate the wider significance of complex multi-host–multi-parasite interactions as drivers of host–pathogen community structure
Resumo:
AIMS AND OBJECTIVES: This cross sectional descriptive study was designed to survey patient opinion towards dental clinical attire, name badges and commonly used cross-infection control measures.
METHOD: Patients attending a dental hospital for a consultation appointment were asked to complete a questionnaire accompanied by photographs of models portraying a range of clinical attire. A representative sample of patients completed 188 questionnaires over a four week period.
RESULTS: The study found that the majority of patients felt clinical attire was important and that they preferred dental professionals to wear name badges. The majority of patients also preferred dentists to use both safety glasses and face masks. When asked to indicate which clinical attire was most appropriate for a consultant/specialist to wear, the overwhelming opinion was that of smart dress accompanied with a white coat. In addition, most respondents wished their dentist to wear a traditional white, dental tunic.
CONCLUDING REMARKS: It is hoped that this study will be informative for the dental team and that the results will be taken into consideration when considering appropriate clinical attire in accordance with patient opinions.
Resumo:
The conventional wisdom in the transitional justice literature is that there is no one-size-fits-all approach. This article suggests that this may also be true within a given state. The current paper reports on quantitative and qualitative data from 184 participants in a survey conducted in the Caribbean coast of Colombia. Results suggest widespread support for transitional justice mechanisms – such as perpetrator accountability, public acknowledgement and structural change – but dissatisfaction with national-level initiatives, specifically the 2005 Justice and Peace Law. Yet, despite a distrust of the national government and protracted conflict, individuals report social trust, community cohesion and reliance on local government institutions. These attitudes and behaviours suggest that decentralised transitional justice mechanisms may be more effective in meeting victims' needs. Moreover, analyses indicate that individual preferences are influenced by community factors, such as the presence of demobilised paramilitaries, which can be addressed through more localised approaches to promote peacebuilding. The paper concludes with best practices derived from the findings.
Resumo:
The end of Dennard scaling has pushed power consumption into a first order concern for current systems, on par with performance. As a result, near-threshold voltage computing (NTVC) has been proposed as a potential means to tackle the limited cooling capacity of CMOS technology. Hardware operating in NTV consumes significantly less power, at the cost of lower frequency, and thus reduced performance, as well as increased error rates. In this paper, we investigate if a low-power systems-on-chip, consisting of ARM's asymmetric big.LITTLE technology, can be an alternative to conventional high performance multicore processors in terms of power/energy in an unreliable scenario. For our study, we use the Conjugate Gradient solver, an algorithm representative of the computations performed by a large range of scientific and engineering codes.
Resumo:
Chiral dienamides, derived from chiral amines and oxazolidinones, react with electron deficient dienophiles Eo give amino-cyclohexanes with good to excellent de's.
Resumo:
Metallo-azomethine ylides, generated from imines by the action of amine bases in combination with LiBr or AgOAc, undergo cycloaddition with both 1R, 2S, 5R- and 1S, 2R, 5S-menthyl acrylate at room temperature to give homochiral pyrrolidines in excellent yield. The stronger the base the faster the cycloaddition and the greater the yield with: 2-t-butyl-1,1,3,3-tetramethylguanidine > DBU > NEt(3) X-Ray crystal structures of representative cycloadducts establish that the absolute configuration of the newly established pyrrolidine stereocentres is independent of the metal salt and the size of the pyrrolidineC(2)-substituent for a series of aryl and aliphatic imines.
Resumo:
4-Amino-5-hexynoic acid is efficiently synthesised in eight steps (overall yield 10%) from commercially available (S)-glutamic acid. The key step was conversion of an aldehyde to an acetylene using diethylmethydiazophosphonate.